How the Eye and Sight Work

The eye is one of the most complex parts of human anatomy. Just like the foot has a huge percentage of the total bones in your body, the eye has many layers and many moving parts inside of it that renders it one of the most complex, yet one of the most beautiful parts of the human body. The easiest way to understand how the eye works is to see a cut model that shows you the various layers, nerves, parts, lenses and light receptors that all work together to create the vision that we all cherish so much.

While it may sound like a bit of a cliché, vision starts with one important thing: light. Without it, the various light receptors in the eye can’t do their job and there would literally be nothing to see. The point of your eye, above all else, is to focus light properly. You will need glasses, contact lenses, bifocals, trifocals or even LASIK surgery if your eyes have problems focusing light properly. The eye essentially works like a camera, with some differences. The fact that the images your eye sees are actually upside down is an interesting fact. It is only through the optical nerve and the processing centers in your brain that those images are flipped and the world makes sense.

Vision begins once light enters into the eye through your cornea. The cornea is the very outer layer of your eye. The cornea is almost like a pair of eyeglasses for your eye. It helps to focus the light so that objects directly in front of you, objects a little farther away from you and objects a long ways from you all make sense. Needless to say, the cornea is one of the hardest working parts of your body. The light then passes through the lens of your eye where the focusing is increased to the point where a far better picture is taken of whatever you are looking at. Finally, the retina, which is located at the very back of the eye, receives the light. Your retina is comparable to the film that is inside of a camera (back when film was actually used.) Your retina has the ability to change light, and the information given to it by the rest of the eye, into electrical impulses that can be fed directly to your brain and turned into images that you understand. As amazing as your retina is, it does take specific fine tuning for it to work properly. Low light, interference due to an object in your eye or simply turning your head too fast can cause disruptions in your vision that significantly reduce the clarity of what you see. To put it another way, your eye works as a very sensitive camera, but it could benefit from additional image stabilizers as well as a few other upgrades that would allow it to see in various circumstances better.

The retina makes use of the optic nerve to send much of its information from the eye to the brain. Often times, the most serious eye injuries a person can suffer from are injuries that damage or sever the optic nerve in some way. There are also a number of diseases that can attack the optical nerve and damage your ability to see clearly for long periods of time. When you go to the eye doctor, the health of the optical nerve is often checked. This way, if it appears that you are suffering from a degenerative condition, it can be diagnosed and treated early on.

Another part of the eye that is very important is the cones. Cones are located in the retina of your eye and help to detect color. It is thought that the average person has approximately 150 million color distinguishing cones in their eyes. As you age, older cones die off and new ones are grown. Conditions such as color blindness happen when cones that detect green or red are absent from inside of your eye. Approximately 8 percent of all men suffer from this condition and less than one percent of women do. It is a hereditary condition that is untreatable at this time. The myth that a color blind person can’t see either green or red is slightly inaccurate. The major problem is that a person suffering from color blindness often confuses the two colors.

Yet another important part of proper vision is the eye’s use of a chemical known as retinal. This chemical is made, in large part, from Vitamin A. A lack of Vitamin A in your diet can lead to a condition known as night blindness, which is the inability to see in low light situations. During daylight hours, this deficiency of retinal isn’t an issue because there is more than enough light for a person to be able to see, but during the night, the lack of retinal in the eye leads to light receptors not being sensitive enough to pick up moonlight.

It can be said with no controversy that the eye is an extremely delicate part of the human anatomy. What is even more amazing is how many common eye conditions can be treated in this day and age, often times through the use of eyeglasses. Everything from nearsightedness to farsightedness can be treated and with regular eye exams, the eye can continue to be fully functional well into old age.

When you consider the incredibly small size of the human eye, approximately one inch wide, one inch deep and one inch tall, it provides the single most important service to our bodies. Thanks to a constant intake of data, light, images and colors, we are able to complete incredibly complex tasks that other species can’t. It is only with proper care, however, that we are able to make the most of our vision and preserve it for decades to come. Talk to your eye doctor today about an eye exam and see if you need eyeglasses for any of the various conditions that exist.

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